GEOG 101: Day 13

1. Fresh Water GEOG 101: Day 13 New film just released in the theatres: “Watermark” by Jennifer Baichal and Edward Burtynski; see also films by Paul Manley, and “Blue Gold,” “Water Wars,” etc.

2. Housekeeping Items • I hope you had a good Thanksgiving weekend. • Today is the due date for the alternative assignment (that replaces the mid-term). • I will hand back as many outlines today as possible. • Other announcements? • One announcement that I have is that the Geography Department and the North Island chapter of Planning Institute of BC are co-sponsoring the 8th Annual Urban Issues Film Festival on campus on Friday, November 8th on the broad theme of “water and planning.” Volunteers are always welcome and we are having an organizing meeting in the library portion of Jumping Java today at 4 p.m.

3. 12-3

4. Upon successfully completing this chapter, you will be able to • Explain the importance of water and the hydrologic cycle to ecosystems, human health, and economic pursuits • Delineate the distribution of fresh water on Earth • Describe major types of freshwater ecosystems • Discuss how we use water and alter freshwater systems • Assess problems of water supply and propose solutions to address depletion of fresh water • Assess problems of water quality and propose solutions to address water pollution • Explain how waste water is treated

5. Canadians fear we will place our sovereignty at risk is we allow large-scale diversions of fresh water • Once they start, they will be impossible to stop • Some view water as a marketable commodity, others say we should not consider exporting it to those have mismanaged theirs. • Canada’s fresh water is protected as each province and territory prohibits bulk water exports • “The wars of the twenty-first century will be fought over water.” • – World Water Commission Chairman Ismail Serageldin

6. Freshwater Systems 12-6

7. Freshwater systems • Water may seem abundant, but drinkable water is rare • Freshwater = relatively pure, with few dissolved salts • Only 2.5% of Earth’s water is fresh, most is tied up in glaciers and ice caps. Of the 21% that is not, only 53% is in rivers, lakes or groundwater.

8. Rivers and streams wind through landscapes • Water from rain, snowmelt, or springs forms streams, creeks, or brooks • These merge into rivers, and eventually reaches the ocean • Tributary = a smaller river slowing into a larger one • Drainage basin or watershed = the area of land drained by a river and its tributaries

9. Rivers and streams wind through landscapes (cont’d) • If there is a large bend in the river, the force of the water cuts through the land • Oxbow = an extreme bend in a river • Oxbow lake = the bend is cut off and remains as an isolated, U-shaped body of water

10. Rivers and streams wind through landscapes (cont’d) • Floodplain = areas nearest to the river’s course that are flooded periodically • Frequent deposition of silt makes floodplain soils fertile • Riparian = riverside areas that are productive and species-rich • Water of rivers and streams hosts diverse ecological communities

11. Wetlands include marshes, swamps,and bogs • Wetlands = systems that combine elements of freshwater and dry land • Freshwater marshes = shallow water allows plants to grow above the water’s surface • Swamps = shallow water that occurs in forested areas • Can be created by beavers • Bogs = ponds covered in thick floating mats of vegetation • A stage in aquatic succession

12. Wetlands include marshes, swamps, and bogs (cont’d) • Wetlands are extremely valuable for wildlife • They slow runoff • Reduce flooding • Recharge aquifers • Filter pollutants • People have drained wetlands, mostly for agriculture • Southeastern (Potholes region) Canada has lost more than half of their wetlands

13. Lakes and ponds are ecologically diverse systems • Lakes and ponds are bodies of open, standing water • Littoral zone = region ringing the edge of a water body • Benthic zone = extends along the entire bottom of the water body • Home to many invertebrates • Limnetic zone = open portions of the lake or pond where the sunlight penetrates the shallow waters • Profundal zone = water that sunlight does not reach • Supports fewer animals because there is less oxygen

15. Lakes and ponds are ecologically diverse systems (cont’d) • Oligotrophic lakes and ponds = have low nutrient and high oxygen conditions • Eutrophic lakes and ponds = have high nutrient and low oxygen conditions • Eventually, water bodies fill completely in through the process of succession • Inland seas = large lakes (such as the Great Lakes and, formerly, the Aral Sea that hold so much water, their biota is adapted to open water

16. Groundwater plays key roles in the hydrologic cycle • Groundwater = precipitation that does not evaporate, flow into waterways, or get taken up by organisms • Aquifers = Porous sponge-like formations of rock, sand, or gravel that hold groundwater • Zone of aeration = spaces are partially filled with water • Zone of saturation = spaces are completely filled with water • Water table = boundary between the two zones • Aquifer recharge zone = any area where water infiltrates Earth’s surface and reaches aquifers

17. A typical aquifer

18. Groundwater plays key roles in the hydrologic cycle (cont’d) • Confined or artesian = water-bearing, porous rocks are trapped between layers of less permeable substrate (i.e., clay) • Is under a lot of pressure • Unconfined aquifer = no upper layer to confine it • Readily recharged by surface water • Groundwater becomes surface water through springs or human-drilled wells • Groundwater may be ancient: the average age is 1,400 years

19. Water is unequally distributed across Earth’s surface • Many areas with high population density are water-poor and face serious water shortages

20. Climate change will cause water problems and shortages • Climate change will affect the hydrologic cycle: • Shift northward in mid-latitude rain belt • Earlier snowmelt and spring runoff • More evapotranspiration • Drier summers in the interior continental region • Additional impacts: • Warmer rivers (impacting fish) • Lower water levels in Great Lakes • Higher ocean water levels

21. How We Use Water 12-21

22. How we use water • We have achieved impressive engineering accomplishments to harness freshwater sources • 60 % of the world’s largest 227 rivers have been strongly or moderately affected • Dams, canals, and diversions • Consumption of water in most of the world is unsustainable • We are depleting many sources of surface water and groundwater • One-third of the world’s people are already affected by water scarcity

23. Water supplies houses, agriculture, and industry

24. Water supplies houses, agriculture, and industry (cont’d) • Consumptive use = water is removed from an aquifer or surface water body, and is not returned • Non-consumptive use = does not remove, or only temporarily removes, water from an aquifer or surface water • Electricity generation at hydroelectric dams

25. We have erected thousands of dams • Dam = any obstruction placed in a river or stream to block the flow of water so that water can be stored in a reservoir • To prevent floods, provide drinking water, allow irrigation, and generate electricity • 45,000 large dams have been erected in more than 140 nations • Only a few major rivers remain undammed • In remote regions of Canada, Alaska, and Russia

26. A typical dam

27. Benefits: Power generation Emission reduction Crop irrigation Drinking water Flood control Shipping New recreational opportunities Drawbacks: Habitat alteration Fisheries declines Population displacement Sediment capture Disruption of flooding Risk of failure Lost recreational opportunities Benefits and drawbacks of dams

28. China’s Three Gorges Dam is the world’s largest • 186 m high and 2 km wide, completed in 2006 • When filled it will be as long as Lake Superior • It has cost $25 billion to build, flooded 22 cities and the homes of 1.24 million people, submerged 10,000 year-old archaeological sites, productive farmlands, and wildlife habitat, and causing erosion below the dam • Some fear pollutants will also be trapped in the reservoir, making water undrinkable • Two films about: “China’s Three Gorges Dam” and Still Life.” 12-28

29. Some dams are now being removed • Some people feel that the cost of dams outweighs their benefits • Rivers with dismantled dams • Have restored riparian ecosystems • Reestablished fisheries • Revived river recreation • In Canada only a few dams have been decommissioned but 500 dams have been removed in the U.S. “YOSEMITE NATIONAL PARK, Calif. — An environmental artist with the skills of a mountain climber painted a giant crack down the face of HetchHetchy Reservoir dam, park officials said Monday. "It was really a work of art--it wasn't just graffiti," said Dean Coffey, general manager with the HetchHetchy Water and Power District, which provides water to San Francisco and surrounding communities. ‘Whoever did it has a lot of pride.’”

30. Dikes and levees are meant to control floods • Flooding is a normal, natural process • Floodwaters spread nutrient-rich sediments over large areas • Floods also do tremendous damage to property • Dikes and levees (long, raised mounds of earth) along the banks of rivers hold rising waters in channels • Levees can make floods worse by forcing water to stay in channels and overflow

31. We divert – and deplete – surface water to suit our needs • Diversion has drastically altered the river’s ecology • What water is left in the Colorado River after all the diversions comprises just a trickle into the Gulf of California and Mexico

32. We divert – and deplete – surface water to suit our needs (cont’d) Aral Sea - once the fourth-largest lake on Earth lost over 80% of its volume in 45 years from diversion Consequences Lost 60,000 fishing jobs Pesticide-laden dust from the lake bed is blown into the air The cotton cannot bring back the region’s economy

33. We divert – and deplete – surface water to suit our needs (cont’d) People may have begun saving the northern part of the Aral Sea

34. Inefficient irrigation wastes water • Today, 70% more water is withdrawn for irrigation than in 1960 • The amount of irrigated land has doubled • Crop yields can double • Only 45% of water is absorbed by crops via “flood and furrow” irrigation • Overirrigation leads to waterlogging, salinization, and lost farming income • Most national governments subsidize irrigation • Water mining = withdrawing water faster than it can be replenished

35. Areas where water use exceeds supply; will get worse with climate change

36. weighingtheissues Flood protection at what cost? In May 2011, during record high-water levels on the Assiniboine River, the government of Manitoba deliberately breached a dike near Portage-la-Prairie, with the goal of releasing pressure in the Portage Reservoir and averting a much larger, uncontrolled flood. The controlled release put 150 homes and a considerable area of farmland at risk. In the end, the controlled breach worked, and no homes in the threatened area were significantly harmed.

37. weighingtheissues Flood protection at what cost (cont’d)? A similar situation occurred during the Red River Floodway of 1997, during which the Red River Floodway diverted floodwater to protect the city of Winnipeg, but perhaps at the cost of flooding in smaller communities such as St. Agathe. Both events caused significant stress for those in the path of diverted floodwaters. • If you were a decision maker in Manitoba, would you have reached the same decision? • Is it worthwhile to protect certain areas, even if it means risking others? • What might you do to compensate those who were at risk?

38. Wetlands have been drained for a variety of reasons • Promote settlement and farming • Seen as useless “swamps” • Ramsar Convention in 1971 • Global concern for wetland loss and degradation • Promotes local, regional, and national actions and international cooperation • 90% of original wetlands in southern Canada have been lost

39. We are depleting groundwater • Groundwater is easily depleted • Aquifers recharge slowly • 1/3 of world population relies on groundwater • As aquifers become depleted • Water tables drop • Salt water intrudes in coastal areas • Sinkholes = areas where ground gives way unexpectedly • Some cities (Venice, Mexico City) are slowly sinking • Wetlands dry up

40. Our thirst for bottled water seems unquenchable • Canadians’ use of bottled water only surpassed by U.S. • University-educated households were shown to be less likely to consume bottled water • Average capital use in 2003 was almost 50 L of bottled water • Most bottled water is nothing more than tap water, sometimes with additional filtering or other treatment • Canada’s Food and Drug Act does not require a manufacturer to obtain a licence to bottle water 12-40

41. weighingtheissues The price of a litre • Do you drink bottled water? Why? • Do you think it is safer than municipal water? Do you prefer the taste? • What do you pay for a litre of bottled water? What do you pay for a litre of gas at the pump? • What do you think should be reflected in these prices? • What price do you think was paid for the water by the company that bottled it? • What about the source of the water you consume— is it groundwater and, if so, is its source adequately protected? • And what about the plastic waste that is generated?

42. Will we see a future of water wars? • Freshwater depletion leads to shortages, which can lead to conflict • 261 major rivers cross national borders • Water is a key element in hostilities among Israel, Palestinians, and neighboring countries • Many nations have cooperated with neighbors to resolve disputes • India, Pakistan, Bangladesh, Bhutan, and Nepal

43. Solutions to Depletion of Fresh Water 12-43

44. Solutions can address supply or demand • We can either increase supply or reduce demand • Lowering demand • Politically difficult in the short term • Offers better economic returns • Causes less ecological and social damage • Increasing supply • Water can be transported through pipes and aqueducts • It can be forcibly appropriated from weak communities

45. Desalinization “makes” more water • Desalinization = the removal of salt from seawater or other water of marginal quality • Distilling = hastens evaporation and condenses the vapor • Reverse osmosis = forces water through membranes to filter out salts • Desalinization facilities operate mostly in the arid Middle East • It is expensive, requires fossil fuels, and produces concentrated salty water

46. Agricultural demand can be reduced • Look first for ways to decrease agricultural demand • Lining irrigation canals • Low-pressure spray irrigation that spray water downward • Drip irrigation systems that target individual plants • Match crops to land and climate • Selective breeding and genetic modification to raise crops that require less water

47. We can lessen residential and industrial water use in many ways • Eat less meat (1 kg of beef = 13-15,000 litres) • Install low-flow faucets, showerheads, washing machines, and toilets • Use automatic dishwashers instead of washing dishes by hand • Water lawns at night, when evaporation is minimal, or replace lawn with native plants • Xeriscaping = landscaping using plants adapted to a dry environment

48. We can lessen residential and industrial water use in many ways • Shift to processes that use less water • Wastewater recycling (separating greywater and brown water, and re-using former) • Excess surface water runoff used for recharging aquifers • Patching leaky pipes • Auditing industries • Promoting conservation/education

49. Economic approaches to water conservation are being debated • End government subsidies of inefficient practices • Let the price of water reflect its true cost of extraction (the tar sands use huge amounts of freshwater and contaminate the water that is released back into river systems) • Industrial uses are more profitable than agricultural • Privatization of water supplies • May improve efficiency • Firms have little incentive to provide access to the poor • Decentralization of water control may conserve water • Shift control to the local level

50. Freshwater Pollution and Its Control 12-50